Device for checking the run of the thread in a draw twisting frame or the like



April 26, 1966 R. JAEGGLI DEVICE FOR CHECKING THE RUN OF THE THREAD IN A DRAW TWIS'IING FRAME OR THE LIKE Filed Dec. 50, 1963 INVENTOR. Ruaou' JflfGGL/ K4 flrromvsy 3,247,662 DEVICE FOR CHECKING THE RUN OF THE THREAD IN A DRAW TWISTING FRAME OR THE LIKE Rudolf Jaeggli, W interthur, Switzerland, assignor to Rieter Machine Works Ltd., Winterthur, Switzerland, a corporation of Switzerland Filed Dec. 30, 1963, Ser. No. 334,414 Claims priority, application Switzerland, Jan. 5, 1963, 23/63 Claims. (Cl. 57-81) The present invention relates to means for checking the run of the thread on a draw twisting frame or on a draw winding frame, or the like.

Particularly when warm drawing endless, synthetic threads on draw-twisting frames it has been found un- United States Patent 0 avoidable to continuously check at various locations of the path of the thread whether thread is present at the check points. Hitherto a feeler has been used which rests at a minimum pressure on the passing thread and which moves into a rest position if there is no thread, actuating a switch which initiates a control signal. This arrangement has considerable disadvantages. If the feeler is placed in the drawing zone, the friction may cause breakage of fibrils. If the feeler is placed above the eyelet or thread guide provided above the spindle of a draw twisting frame, the force applied to divert the thread increases the winding tension of the thread which is not desired. This force, therefore, should be little, but if it is so, little power is available for actuating the switch which initiates the control signal. Thread detectors are known which produce greater power and operate with a snap action. These detectors are not fully automatic and must be manually returned to active position.- They respond not only to the absence of thread but also to decreasing thread tension, for example when dofling a package, and must be manually reset whenever they snap into rest position. Electronic thread checking apparatus are expensive.

It is an object of the present invention to provide means for checking the presence of thread at at least one point of the path of a thread in, or adjacent to, a draw twisting frame or the like, which means avoids the aforedescribed difiiculties experienced with conventional thread checking devices. According to the invention the deviating rollers associated with the godet rollers used in drawor draw-winding frames and the like, are resiliently so supported that they can only move ona predetermined path between two extreme positions and are resiliently urged to move away from the godet roller, used to form a drafting zone, into one extreme position. The force acting on the roller for accomplishing this is smaller-than the resultant of the tensions of all threads passing over the roller and urging the deviating roller toward the godet roller.

In a preferred embodiment of the invention the predetermined path on which the deviating roller can move between two predetermined extreme positions is defined by supporting the deviating roller on a lever or arm swingable between two abutments.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing wherein:

FIG. 1 is a diagrammatic illustration of a conventional thread detector in a draw twisting frame.

FIG. 2 is a diagrammatic illustration of a conventional FIG. 4 is a diagrammatic illustration of a modified thread checking and detecting arrangement according to the invention.

In the conventional arrangement shown in FIG. 1 of the drawing a continuously supplied thread package consisting of a plurality of individual fibrils and henceforth called thread 1 moves around a godet roller 2 to a deviating roller 3 and once more around the roller 2 and therefrom to a drawing zone 4. The thread is pulled from the drawing zone, which may be provided with a heater 5, by a godet roller 6 which rotates faster than the roller 2, and by a deviating roller 7 associated with the roller 6. Thereafter the thread moves past a feeler roller 8 forming part of a thread detector 9 through an eyelet or thread guide 10 to a twisting spindle 11 for twisting and winding. The thread may be wound without twisting onto a bobbin driven by a friction roller as indicated by numeral 12 in FIG. 2. As shown in FIG. 1 and 2 the thread is bent out of a straight path by the feeler 8. If there is no force acting as the resultant of the tensions of the thread running on and off the feeler roller 8, as is the case, for example, when the thread is broken, a spring 8 moves the feeler roller 8 to the position shown by a dotted line in FIGURES 1 and 2 and closes a control circuit 13.

In contradistinction to the aforedescribed conventional thread detectors which constitute additional apparatus, in the system according to the invention the deviating rollers which are associated with the godet rollers and are present in any case are used for checking the run of the thread. To accomplish this the deviating roller 7' is mounted on a support 14 which is swingably connected by a plate spring 15 to a stationary part 16 of the draw twisting frame. The device is shown in FIG. 3 in the position when the spring 15 is tensioned by the effect of the tension of the thread 1 passing around the roller 7'. If there is no thread tension, the spring 15 presses the support 14 and the roller 7' to the position shown by dash-dot lines in FIG. 3. Movement of the support 14 by the spring 15 is limited by an abutment 17. If there is thread tension, the roller 7' is moved upward until the support 14 meets an abutment 18. A switch 21 controlling a circuit 20 is connected to the support 14 by means of a link 19. Downward movement of the roller 7' by the spring 15, when the thread tension is insuflicient, places the switch 21 in a position closing the circuit 20 to actuate means, not shown, for producing an optical or acoustic warning signal or the like.

In the modification of the apparatus according to the lnvention shown in FIG. 4 the swing axis of an arm 22 is substantially parallel with the rotation axis of the godet roller 2. The arm 22 is swingable between two abutments 24 and 25. The arm 22 is rigid and a spring 26 is provided urging the arm to swing upward and abut against the abutment 25 when there is no thread tension acting on the deviating roller 3 which is rotatably mounted on the arm 22; The force of the spring 26 is such that the resultant of the thread tension forces can move the arm 22 against the action of the spring downward to abut against the abutment 24. A switch 27 forming part of a suitable control circuit is operatively connected to the arm 22.

I claim: 1. In combination with a draw twisting frame and like machinery:

at deviating roller,

a godet roller,

a tension thread running from said godet roller around said deviating roller and back to said godet roller,

support means swingably supporting said deviating roller and affording swinging of said deviating roller on a predetermined path away from and toward said godet roller,

resilient means operatively associated with said support means for urging said deviating roller to swing away from said godet roller,

the force of said resilient means being less than the force of said thread acting on said deviating roller and switch means interposed in a control circuit and operatively connected to said support means for actuation of said switch means upon swinging of said support means away from said godet roller due to absence of sufficient thread tension to overcome the action of said resilient means.

2. In the combination defined in claim 1: stationary means, said support means including an arm swin-gably connected to said stationary means, said resilient means being interposed between said stationary means and said arm.

3. In the combination defined in claim 2: two stationary and spacer'abutments for limiting swinging of said arm in either direction.

4. In combination with a draw twisting frame and like machinery: t

stationary means,

a deviating roller,.

a godet roller,

a tensioned thread running from said godet roller-onto said deviating roller and back to said godet roller, support means including a rigid portion rotatably supporting said deviating roller, said support means ineluding a resilient part connecting said rigid portion to said stationary means and urging said rigid portion away from said godet roller with a forcesmaller than the force caused by the tensioned thread and urging said deviating roller toward said godet roller and switch means interposed in a control circuit and operatively connected to said rigid portion for actuating said switch means upon movement of said rigid portion away from said godet roller due to the absence of sufiicient force caused by the tensioned thread for overcoming the force exerted by said resilient part.

5. In the combination defined in claim 4: two stationary, spaced abutments engageable by said rigid portion 15 and defining the extreme positions of said rigid portion away from and toward said godet roller.

References Cited by the Examiner 9 UNITED STATES PATENTS 2,218,504 10/1940 Cadden 28-71.3 2,474,912 7/1949 Pollock 2s-71.4 2,789,316 4/1957 Miller et a1 2859.5 X

FOREIGN PATENTS 25 68,684 2/1949 Denmark 2s- 71.3 98,626 7/1961 Netherlands 28-713 MERVIN STEIN, Primary Examiner. 

1. IN COMBINATION WITH A DRAW TWISTING FRAME AND LIKE MACHINERY; A DEVIATING ROLLER, A GODET ROLLER, A TENSION THREAD RUNNING FROM SAID GODET ROLLER AROUND SAID DEVIATING ROLLER AND BACK TO SAID GODET ROLLER, SUPPORT MEANS SWINGABLY SUPPORTING SAID DEVIATING ROLLER AND AFFORDING SWINGING OF SAID DEVIATING ROLLER ON A PREDETERMINED PATH AWAY FROM AND TOWARD SAID GODET TOLLER, RESILIENT MEANS OPERATIVELY ASSOCIATED WITH SAID SUPPORT MEANS FOR URGING SAID DEVIATING ROLLER TO SWING AWAY FROM SAID GODET ROLLER, THE FORCE OF SAID RESILIENT MEANS BEING LESS THAN THE FORCE OF SAID THREAD ACTING ON SAID DEVIATING ROLLERR AND SWITCH MEANS INTERPOSED IN A CONTROL CIRCUIT AND OPERATIVELY CONNECTED TO SAID SUPPORT MEANS FOR ACTUATION OF SAID SWITCH MEANS UPON SWINGING OF SAID SUPPORT MEANS AWAY FROM SAID GODET ROLLER DUE TO ABSENCE OF SUFFICIENT THREAD TENSION TO OVERCOME THE ACTION OF SAID RESILIENT MEANS. 